and help with the clutter in the closet. kris sanchezshowsusanationwide swap site that could help you. >> reporter: baby kiley is so big and getting bigger every day, so is her 5-year-old sister, and that means mom has a growing problem, too. >> it seems like with two kids you are always overflowing with clothes. >> reporter: piles and piles of clothes that don't fit but still have life in them. born of this problem, the bay area's national online children's clothing swap. >> as soon as you register as a user on threadup.com you will receive shipping boxes. you take the box, fill it up with the clothing and you list it as available for a swap. when someone chooses your box as swap, the company will arrange for the pick up, and you leave it and the mailman picks it up. in the meantime you browse for boxes that you want sent to you. total cost, 13 bucks. >> once the kids are asleep, i'm watching my tv and on the internet searching. that's when i do my listing of boxes. i bring out my old clothes. i roll them up, put them in the box. >> reporter: members who join for free get a brief des